Tunnel liner and method of making same



v June 17, 1969 J. R. TABOR v TUNNEL LINER AND METHOD OF MAKING SAME Filed July 12, 1967 United States Patent M 3,449,916 TUNNEL LINER ANS? METHOD OF MAKING AME John R. Tabor, 3400 Spruce St., Racine, Wis. 53403 Filed July 12, 1967, Ser. No. 652,949 Int. Cl. E21d 11/08; E01g /02; E04c 1/10 US. Cl. 61-45 7 Claims ABSTRACT 53F THE DISCLOSURE A tunnel liner and method of making same having a plurality of blocks in a circle, and with the radially inside surface of the circle of blocks having a cylinder of concrete cast thereon. The blocks have metal pieces cast therein, and the opposite ends of the metal pieces extend beyond the concrete portions of the blocks. The extending ends of the metal pieces are preferably mechanically joined together, and the cylinder of concrete is cast around the extending ends of the metal pieces to imbed the extending ends in the cylinded of concrete.

Background of the invention This invention relates to a tunnel liner and method of making same. The liner disclosed utilizes concrete blocks which are disposed in a circle and are particularly useful in lining the wall of a tunnel in the ground.

The prior art has employed concrete blocks for lining ground tunnels, but certain types of these blocks are without any reinforcing pieces therein, and the blocks are disposed to be generally in end-to-end abutment in their concrete portions. Also, heretofore a large number of blocks have been required for completing the single course of the circumference of the liner. However, other types of blocks are known to have metal pieces imbedded therein, and they have also been known to have attaching means for presenting tensile connectors between the blocks. Examples of tunnel liner installation, block construction, and tunnel liners and methods of making them are shown in U.S. Patents 1,336,789, 1,624,369, 1,881,421, and 1,670,625, for instance. The first patent shows generally the installation of the liner and the formation of a tunnel; the second patent shows means for connecting blocks together; the third patent shows tunnel blocks with metal pieces cast'therein; and the last patent shows generally the mechanical connectors between courses of blocks, though not between blocks within a course, and it shows the final lining of the tunnel with a cylinder of concrete.

The prior art recognizes the desirability of combining metal and concrete in the formation of the liner. However, it has not found a desirable way of providing for precast blocks with reinforcement pieces therein, and with the reinforcement pieces being available for mechanical connection between each other, and with the final provision of the inside cylinder of concrete imbedding the reinforcing pieces in concrete at their extended ends. Thus the result of the liner with characteristics of a continuous hoop of metal imbedded in a continuous cylinder of concrete, in the arrangement described herein, has not been accomplished by the liners known heretofore. Further, where a hoop of metal may have been provided in tunnel liners, it then necessitated supporting the hoop and casting concrete in a cylinder to imbed the hoop, to achieve the liner of the present invention. This entailed the handling of the metal and concrete separately and on the job site, rather than precasting the blocks with reinforcing metal therein as in the present invention. The problem of casting the blocks or the concrete for imbedding metal on the job site is well known to be a difficult task. Still further, in the common construction of a liner and its 3,449,916 Patented June 17, 1969 installation, it is desired to employ the liner blocks themselves for advancing the tunneling machine and for supporting the tunnel by the blocks as the tunnel is being cut into the ground, rock, or whatever, and this invention permits that.

Thus the general objects of this invention include the provision of a tunnel liner which is of maximum strength, easy to install, requires only a minimum of labor and time in installation, and herein at least a portion of the liner can be precast at the factory, the liner structure has maximum strength in both tensile and compressive strength, the outer cylinder of the liner is relatively smooth and makes it easy for working within the liner outer cylinder in forming the poured inner cylinder of concrete, and there is a substantial saving in grouting.

Brief description of the drawing FIG. 1 is an end view of the tunnel liner, showing the interior cylinder of concrete in section and showing the nature of the form for supporting the concrete while it is being poured and setting.

FIG. 2 is an enlarged view of a fragment of FIG. 1.

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2.

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 2, and having concrete added thereto.

FIG. 5 is a top view of another embodiment of a joint employed between the blocks.

FIG. 6 is a front view of FIG. 5.

Description 0 the method and preferred embodiments The tunnel liner is shown to consist generally of the outside cylinder designated 10 and the inside cylinder designated 11. The cylinder 10 includes a plurality of concrete blocks generally designated 12 and being mainly formed of concrete material through intermediate con crete portion 13. A reinforcing metal piece 14 is disposed within each block and has extending ends 16 and 17 projecting beyond the end walls 18 and 19, respectively, of the concrete portion 13 of each block. Thus the blocks 12 are precast and are of an arcuate shape, and it is also significant to note that only 3 blocks are utilized for ma king a complete circle of one course of blocks, and this in reality could be on a diameter of any feet, say for instance 25 feet. The precast blocks 12 are therefore made under the conditions of factory manufacture, rather than job-site manufacture, and they are installed in their endto-end relation shown to form the cylinder 10, and these then are available for supporting the tunnel ground and for the thrust of the tunneling machine which bears against the blocks in the axial direction, in the well-known manner of advancing the tunneling machine. Also, the reinforcing pieces 14 are disposed preferably around the inner surface 21 of the blocks 12 to be fiush with the surface 21 in the arcuate surface 22 of the metal pieces 14. This permits accuracy in alignment of the ends 16 and 17 with the adjacent ends of the adjacent blocks 12. It also permits the metal pieces 14 to form a continuous hoop or ring around the liner, and to have this metal ring disposed on the inside face or surface 21 which is subjected to tensile forces under internal pressure in the liner. Also, the outer cylinder 10 then has the bulk of its concrete through its concrete portion 13 disposed radially outwardly from the metal ring formed by the pieces 14, and this concrete is available for resisting compression both from the exterior as well as from the interior pressures in the tunnel. Such interior pressures may be created by utilizing this tunnel in the conveyance of liquid such as water which would of course create pressure radially outwardly on the tunnel liner.

FIGS. 2 and 3 clearly show that the metal piece 14 is an I-beam, and actually three I-beams 23 are imbedded in each of the blocks 12. However, only one or any other number could also be used. The extending ends 16 and 17 are then provided with a plate 24 and 26, respectively,

and these plates have holes 27 which are axially aligned and snugly receive a bolt 28 for mechanically securing the ends 16 and 17 together.

To further secure the joint, plates 29 and 31 may be used across the joint between the extending ends 16 and 17. Of course the plates 24 and 26 may be welded, or otherwise aflixed to the ends 16 and 17. Likewise, the plates 29 and 31 may be welded or otherwise secured to the ends 16 and 17, after the joint is made. Thus the ends 16 and 17 are securely mechanically fastened together by means of the plates 29 and 31 and also by means of the bolt or bolts 28.

A cover and protective plate 32 is laid across the gap between the block surfaces 18 and 19, and this plate 32 serves to retain the ground or like material out of the liner and to support the liner in the finished form.

FIG. 1 shows that the crown of the liner has been expanded to receive a filler piece 33 which may also be in the form of an I-beam and which has its opposite ends bolted to the extending ends 16 and 17 of the adjacent blocks 12. Also, attaching and support plates 34 and 36 span the joint at the crown, and these plates may be Welded or otherwise secured to the extending ends 16 and 17 Still further, a cover or support plate 37 spans the gap between the concrete portions of the blocks. Of course the blocks 12 were initially placed in their circular pattern, and they were then radially displaced outwardly to provide room for inserting the filler piece 33, and the radial expansion causes the blocks 12 to go to closer relationship with the tunnel formed in the ground, as desired.

After the cylinder 10 is disposed as shown in FIG. 1, then the inner cylinder 11 can be poured in place, and an inside form 38 may be used for this pouring. Thus the cylinder 11 will form the desired tight and smooth interior, and it will also provide concrete in the space between the concrete portions 18 and 19 of the blocks, as shown in FIG. 4, and designated 39.

FIG. 3 shows a metal reinforcing mesh 41 imbedded in the block 12, and this may extend between the end walls 18 and 19 of the concrete portion 13 for additional reinforcement of the concrete, as desired. Also, the space initially existing between the walls 18 and 19 may be filled with suitable grouting material, and it may also be filled with a portion of the concrete liner 11 extending around and behind the metal ends 16 and 17, as desired.

FIGS. and 6 show another embodiment of the joint between the metal ends 16 and 17. Here it will be noted that mating plates 42 and 43 are secured to the ends 16 and 17 by any suitable means, and welding may be used. The plates 42 and 43 present an aligned opening which snugly receives a pin 44 extending across the plates, as seen in FIG. 5. Additionally, the plates may be assisted in securing the ends 16 and 17 together by means of bolts, such as bolt 46, extending between the plates 24 and 26, as described in connection with the other embodiment. From the foregoing it will he therefore understood that the method of making the liner is also described. Thus the blocks 12 are precast with the metal pieces 14 imbedded therein. The blocks 12 are then initially placed in position, the blocks may be then radially expanded, the filler piece 33 inserted, and all joints can be mechanically secured and grouted, as desired. The interior of the outer cylinder may be cleaned, and then the interior concrete cylinder 11 can be poured and set. Alignment of the extending metal ends 16 and 17 will of course cause alignment of the entire tunnel and will maintain the desired diameter throughout a length of the tunnel. Maintaining the pieces 14 on the interior wall 21 of the blocks 112 permits the desired alignment between the blocks in the final erection.

What is claimed is:

1. In a tunnel liner, a plurality of arcuately shaped precast blocks of concrete disposed in end-to-end relation in a circle to present a complete course of said blocks and a tunnel liner support, a cylinder of concrete disposed around the interior of said tunnel liner support, said precast blocks including a metal piece imbedded therein and extending therethrough and projecting circumferentially beyond the concrete at both said ends of said block to have the adjacent ends of the concrete portions of adjacent blocks spaced apart, said metal pieces being aligned with each other between said adjacent ones of said blocks and being mechanically secured together to present an endless metal hoop through each said course of said blocks, said cylinder of concrete extending integrally into the space between said concrete portions of said blocks, the improvement comprising said metal pieces in adjacent ones of said blocks extending fully across said space and into end-to-end abutting contact with each other for assembly and compressive support on each other, and with said metal pieces being directly secured together.

2. The subject matter of claim 1, wherein said metal piece is arcuately shaped and conforms to the curvature of said arcuately shaped blocks and extends therethrough adjacent the radially inside surface of said blocks to be intermediately imbedded with respect to said cylinder of concrete and the concrete of said concrete portions of said blocks.

3. The subject matter of claim 2, wherein said metal piece is an I-beam, with one flange thereof located flush with said radially inside surface on said concrete portion of said blocks.

4. The subject matter of claim ill, including connectors between said blocks and aflixed to each of the abutting ends of said metal pieces to be capable of transmitting tensile forces between said blocks.

5. The subject matter of claim 4, wherein said connectors include bolts, and said metal pieces have bolt holes for receiving said bolts and indicating alignment between said adjacent blocks.

6. In a method of making a lined tunnel, the steps of precasting blocks of concrete in arcuate shapes and with a metal piece extending beyond the ends of the concrete, disposing said blocks in end-to-end relation to form a circle of said blocks, forcing axially on said circle of said blocks to advance a tunnel shield, securing together the adjacent ends of said metal pieces, radially expanding said circle of blocks, forming a cylinder of concrete around the radially inside surface of the circle of said blocks, the improvement comprising the steps of placing said blocks in said end-to-end relation to have the extending ends of said metal pieces in abutting contact to support one on the other and to have the adjacent ends of the concrete portions of said blocks spaced apart, and casting said cylinder of concrete to have it extend into the spaces between said concrete portions and to imbed the extending ends of said metal pieces and to have said cylinder of concrete extend around the radially inside surface of the circle of said blocks.

7. The method of claim 6, including the step of mechanically connecting said extending ends of said metal pieces directly together prior to imbedding said extending ends in said cylinder of concrete.

References Cited UNITED STATES PATENTS 2,419,329 4/ 1947 Wilson 61-45 FOREIGN PATENTS 12,970 5/ 1911 Great Britain. 7,120 3/1914 Great Britain.

OTHER REFERENCES German printed application, 1,172,289, June 1964.

JACOB SHAPIRO, Primary Examiner.

US. Cl. X.R. 

